1. Field of the Invention
The present invention relates to a tool for a surface mounting device head and a tool automatic changing apparatus thereof, and particularly to a tool for a surface mounting device head and a tool automatic changing apparatus capable of stably aligning parts of a surface mounting device, minimizing vibrations of a suction nozzle retaining corresponding parts thereof, and easily changing the tool and a suction nozzle in operation.
2. Description of the Conventional Art
Recently, electronic parts in the industry become very density and compact size as the electric and electronic products are down-sized. A surface mounting technology has been developed in the industry to meet the demand of the above-mentioned new technology.
Generally, the surface mounting technology is classified into two categories of a surface mounting device and its assembling technology. So, the development of the surface mounting parts is focused on more compact-sized and very-density products. The assembling technology is focussed on the development of its accurate assembling tools necessary for a surface mounting of corresponding parts and its applied technology.
The surface mounting device is capable of surface-mounting the surface mounting parts on a printed circuit board as a major surface mounting assembling device and can be classified into three types of Tape, Stick, and Tray. In addition, the surface mounting device is directed to mounting corresponding surface mounting parts by receiving from a part feeder and positioning them on where the corresponding parts are surface-mounted.
The surface mounting device is generally divided into a high speed type and a standard type, of which the high speed type is used for assembling the corresponding parts in short time, and the standard type is used for assembling various kinds of corresponding parts.
Therefore, the high speed type is good for a mass production but is bad for an accurate surface mounting, so that it is not good for a small amount of products because of its high price. The standard type is not good for the mass production compared with the high speed type, but is good for manufacturing various kinds of surface mounting parts, so that it is good for manufacturing a various kinds of products and a small amount of production. Therefore, the high speed type is good for the mass production, and the standard type is good for accurate parts.
A surface mounting device head capable of automatically mounting corresponding parts on a conventional hybrid circuit is disclosed in U.S. Pat. No. 4,135,630.
As well disclosed therein, the head of a surface mounting device includes a spindle disposed in the central portion thereof and encased by a housing. In addition, two linear grooves parallel to X-axis and Y-axis are formed in the upper portion of the spindle housing.
A central cam is slidably supported by the spindle housing, and is connected to a corresponding part which is linearly moved and a drive rod. In addition, a finger includes a knife edge and a cam surface, in which the knife edge is pivoted in the linear groove of the spindle housing. A spring clamp is directed to evenly retaining the knife edge.
As described above, in the conventional surface mounting device, the central cam downwardly moves when a drive rod downwardly moves when an external linear actuator is activated. In addition, when the central can is downwardly moved, it comes into contact with a cam surface of the finger. Thereafter, the finger is widened about the knife edge.
However, the conventional surface mounting device has disadvantages in that the size of corresponding parts are limited by a rotation angle of the finger because it uses a part alignment type using a pivot, so that the surface mounting alignment becomes unstable, and thus it is hard to prevent the damages of the corresponding parts.
In addition, retaining the corresponding parts by a suction nozzle is unstable because there is no additional construction for preventing vibration of the suction nozzle retaining the corresponding parts. Moreover, it is impossible to change parts such as a tool and a suction nozzle in operation.